The development of control and monitoring system on marine current renewable energy Case study: strait of Toyapakeh - Nusa Penida, Bali

Control and monitoring system is a continuous process of securing the asset in the Marine Current Renewable Energy. A control and monitoring system is existed each critical components which is embedded in Failure Mode Effect Analysis (FMEA) method. As the result, the process in this paper developed through a matrix sensor. The matrix correlated to critical components and monitoring system which supported by sensors to conduct decision-making.


Introduction
Strait of Toyapakeh is located between Bali and Nusa Penida island (shown in Fig. 1). This strait has a good potential of Marine Current energy. Based on the measurement which has been conducted by the researchers in 2015, the Strait of Toyapakeh has the potential Marine Current energy up to 320 mw. The wave amplitude in this strait reached more than 2.6 meters. As other regions in Indonesia, tides type is twice up and down per day [7]. From the reason, Strait of Toyapakeh can be used as the alternatives area to generate the Marine Current energy. The basic principle of marine current energy is to convert kinetic energy to electricity [7]. To support the conditions, communication infrastructure has an important role. The communication infrastructure includes control and monitoring system of Marine Current energy. As the standard of the research, communication for monitoring and control is based on international standard IEC 61400-25. The standard is can be applied on Marine Current Renewable Energy.

Methode scheme of research
Design review is crucial in order to determine failure potential and position by Failure Mode Effect Analysis (FMEA) method. In order to, FMEA describes each part of Marine Current components specifically. Then, the process is continued in control and monitoring system. The design of control and monitoring system of Marine Current Renewable are described in picture bellow:

Figure 2. The Scheme of Control and Monitoring System
According to the scheme, specified function of control and monitoring is designed as early warning system. Mostly, the functions work as local and long distance area. To support long distance area, remote system is required as data communication by telemetry.
In this paper, control and monitoring system is divided into data monitoring, data analysis and processing.   Additional monitoring data to describe the movement, position and orientation platforms are obtained on

Result and discussion
Data processing is change the value based on factors calibration of measurement or change data formats input to others format. In accordance is needed by applying integration, differentiation, Fourier transformation or other methods of data input. Data analysis is conducted to obtain the condition of the system based on sensor data which has been adapted to reflect the needs. Analysis data divided into: 1.Data analysis directly, measured to: -Temperature gearbox -Speed of main shaft 2. Data analysis indirectly, measured to; a) The main shaft torsion: increase or decrease of torsional load can is predicted based on the ratio between the speeds of water flow . In order side, speed blades at a certain point which described as the factor ratio . If the up, it can be considered that the load of main torsional rose as well.
b) The results of the analysis show unreflect on normal operations will be forwarded to control and algorithm alarm (warning or early warning). Control system undertakes the function of control, in order to the process of the system and equipment safety. Control system works on commandment which embedded in processor to a condition reading sensors mounted on equipment on demand. The process control system started with a source of up to a produced output. Therefore, it is divided into the critical component,

Sensor of Load Torsional (Down)
ALARM -

Sensor of Blade Speed Rotation (Down)
ALARM -

Sensor of Shaft Speed Rotation (Down)
ALARM -

Sensor of Load Torsional (Down)
ALARM -

Conclusion
1. The design of control and monitoring system needs to involve failure effect analysis to determine each critical component. 2. The critical component that developed through matrix sensor. 3. The matrix correlated critical components and monitoring system which supported by sensors to do decision-making.